Cam/Crank Code Problem

[JoeR]

Today I looked at a 2008 International 7400 with a Maxxforce DT.  As soon as you start the engine is sets a 4552, Loss of CMP Sync.

The engine had a new OEM CMP sensor.  The owner replaced it after the original one fell apart.  This code was new after replacing the sensor.

I threw moy scope on it and noticed a lot of noise on the circuit.  The noise is enough that I believe it could cause a sync error, and it is WAY noisier than the crank sensor.  Images attached.  With all the noise, ad the way the old CMP sensor had unraveled, I thought maybe there was still some debris on the cam gear.  I put my borescope on it.  There was a little debris on the cam button, but not enough to make the noise I was seeing.

the other thing that is strange is that there appears to be more than one cam button in it, but that isn't reflected in the signal.  It just has lots of noise, not a strange pulse at TDC.

So I have 2 questions:  Has anyone ever seen a double cam button on one of these like this?  Has anyone ever noticed that much noise on a CMP circuit of one of these?  I'm not sure what to chase next on this.  I doubt the new CMP sensor is the problem, but that's a lot of noise.

Borescope pics in next post.

Any advice appreciated.

Joe

[JoeR]

One pic shows the debris.  Next is after I wiped it off.  no other debris was evident as we barred the engine over.  It all looked great.

the 2 buttons do not appear to be the same height, and one is offset from the center, but again, the lab scope shows a great TDC pattern.  It just has extra ones.

[forddieseldoctor]

No idea what is supposed to be in there, but is there a chance that the extra piece is part of the old cam sensor?

And since it’s noisy everywhere else what’s the rest of the cam look like?

[JoeR]

The rest of the gear face looked great.  No foreign objects or anything that might cause any noise.  The second button was not movable with a metal pick, so I just don't know what's going on there.

Thanks for the reply.

Joe

[forddieseldoctor]

Do you have a pic of the old sensor or what was left of it?

And what is the flat surface on the right side of the picture? Is that the bearing journal?

[8WA Sman]

Joe,

Got a Vin and Engine serial #. I ran a Vin from a 2008 that I found online and came up with a 1835985C92 for a cam sensor. Looks similar to a 6.0L sensor is it just me or does that piece look wedged in there?

[JoeR]

13 hours ago, forddieseldoctor said:

Do you have a pic of the old sensor or what was left of it?

And what is the flat surface on the right side of the picture? Is that the bearing journal?

Sorry.  Don't have a pic of the old cam sensor,  The customer pulled more guts out of it before he came in with it, so I don't know what condition it came out of the motor.

The pic was taken in the cam sensor hole.  I believe it should have a single button in it like in the pic here.  However it appears there are 2 cam buttons in there and one of them is offset.  I've never seen anything like that, and it was one of the reasons I was posting here.  I can't imagine why there'd be more than one in there, but they are both solidly mounted.

Joe

[JoeR]

11 hours ago, 8WA Sman said:

Joe,

Got a Vin and Engine serial #. I ran a Vin from a 2008 that I found online and came up with a 1835985C92 for a cam sensor. Looks similar to a 6.0L sensor is it just me or does that piece look wedged in there?

Thanks for the part number.  I do have the VIN. It is 1HTWGAZT98J039297.

Like you, I'm undecided if it is a little crooked.  I didn't care much about it at the time because I was concentrating on what would be causing the extra spikes in the waveform.  The truck is setting a Cam Sync code.  The waveform at TDC looks good, so I was looking for other stuff.  However, you may be on to something.  If that button is not centered perfectly that might cause the code, or at least give us a valid reason to pull the cover.  

Here's a few more pics of it.  

[Bruce Amacker]

I'm not familiar with the extra pin in the picture, and it definitely looks magnetic by the junk stuck to it. Have you tried grabbing it with a magnet on a stick?

 

The 2008 engine will start and run with the CMP disconnected, I've done it before.  The ECM guesses (50% chance) on which stroke the crank is on and fires injectors until it starts.

 

Here's 15 slides from my DT program that are relevant including a CMP/CKP waveform, pictures and other good stuff. The scope wave is from an '07 so the pinout is different but the wave should be the same.

 

IMO, I wouldn't get upset about the noise in your CMP waveform, that is likely normal or a result of your scope settings being set too sensitive. Where were your scope leads? Did you do a CMP/CKP dual trace? In the attached waveform I had my negative scope leads on the battery negative terminal to dampen noise.

 

Your "initial sweep" also seems correct- always look at whether the initial sweep is up or down compared to a known good.  If someone changes the pigtail and switches polarity the sweep reverses.  The engine starts and runs, but poorly.  BTDT, surprised I still have hair after that one.

Sidebar: The scope trainers tell you that the initial waveform can be determined from looking at the ski which has + and - terminals labeled on a PM generator sensor.  Sure enough, they're labeled on Ford and IH skis but the waveform doesn't correlate.

 

Do you have engine skis and the coffee table books for this engine?

 

 

Joe R DTS delete.pdf

[8WA Sman]

The part # I came up with for the cam gear is 1841820C1 and the sensor in the front cover is 1828345C91

[JoeR]

1 hour ago, Bruce Amacker said:

I'm not familiar with the extra pin in the picture, and it definitely looks magnetic by the junk stuck to it. Have you tried grabbing it with a magnet on a stick?

 

The 2008 engine will start and run with the CMP disconnected, I've done it before.  The ECM guesses (50% chance) on which stroke the crank is on and fires injectors until it starts.

 

Here's 15 slides from my DT program that are relevant including a CMP/CKP waveform, pictures and other good stuff. The scope wave is from an '07 so the pinout is different but the wave should be the same.

 

IMO, I wouldn't get upset about the noise in your CMP waveform, that is likely normal or a result of your scope settings being set too sensitive. Where were your scope leads? Did you do a CMP/CKP dual trace? In the attached waveform I had my negative scope leads on the battery negative terminal to dampen noise.

 

Your "initial sweep" also seems correct- always look at whether the initial sweep is up or down compared to a known good.  If someone changes the pigtail and switches polarity the sweep reverses.  The engine starts and runs, but poorly.  BTDT, surprised I still have hair after that one.

Sidebar: The scope trainers tell you that the initial waveform can be determined from looking at the ski which has + and - terminals labeled on a PM generator sensor.  Sure enough, they're labeled on Ford and IH skis but the waveform doesn't correlate.

 

Do you have engine skis and the coffee table books for this engine?

 

 

Joe R DTS delete.pdf 1.96 MB · 3 downloads

hi Bruce,

I tried moving the extra button with a pick.  It didn't move with reasonable force.

Thanks for the lab scope pattern.  I'll do the crank/cm comparison and report back.  

This truck would start without the cam sensor plugged in, but it wouldn't run for more than about 10 seconds, then it would shut off like to turned the key off.  

Speaking of shutting off, I was unable to change the time for the engine idle shutdown timer on this truck.  You can set it to any time you'd like, but you only get 5 minutes whether you like it or not.  Multiple scanners were used, including OEM.  I even tried sliding the min CTS and IAT to disable it, but it didn't change a thing.  Not the first Maxxforce I've seen do that.  The PCM had the latest Cal in it, so maybe it's that way on purpose.

I do not have the skis or coffee table book for this engine.  

Thanks everyone for the help on this.  I appreciate it.

That known good crank/cam correlation pattern is where I need to check next.  

Joe

[Bruce Amacker]

Attached are EGED forms- engine ski and diag sheets.  Also 3 CTB: 2004 and two 2010 CTB- I don't think they published a 2008 CTB but they published two versions of the 2010 CTB. (WTF?!)

 

 Note that IH screws up their "model years"- they're not VIN MY but EPA year, so your 2008 truck is actually a EPA 07 or "2007" model year in IH lingo.  Very misleading. Let me know how you make out, and good luck.

International DT 466, DT 570 and IT 570 I-6 Engines Model Year 2004.pdf EGED375 MF 9, 10, 2008.pdf EGED380 MFDT 2007-2009 Diag sheet.pdf EGED385 MaxxForce DT, 9, 10 diag sheet.pdf MaxxForce 9, 10 DT EPA10 64 pages.pdf MaxxForce DT.9.10 EPA10 85 pages MY 2010.pdf

[JoeR]

I finally got this truck back, but only because it came back on a hook.  The OSS sensor on the trans died and left him stranded.  He's back on the road because he needs the truck every day.  It still sets the same crank/cam code as soon as the engine starts.  I recorded the crank/cam relation with a scope.  I did it with the engine running, but also did it while cranking and at shutoff in case it helped rattle something loose.  It never wavered.  

So the plot thickens on this.  It sets a cam/crank correlation code and the cam/crank correlation is spot on.  The owner is unconcerned about it, as it's not causing any performance problems, but I'd sure like to get it figured out eventually.